1. Field of the Invention
The present invention relates to a zoom lens system, an optical apparatus, and a method for forming an image of an object.
2. Related Background Art
There has been proposed a zoom lens as a high zoom ratio zoom lens, which is composed of, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power, and carrying out zooming by moving each lens group such as Japanese Patent Application Laid-Open No. 2003-241097.
However, such a conventional zoom lens having a low zoom ratio has not sufficiently satisfied the demand for a high zoom ratio. Moreover, when focusing is to be carried out by the second lens group, since a moving amount of the image plane corresponding to slippage (an amount of play) of a stopping position of the focusing lens group becomes large, stopping accuracy of the focusing lens group is required to be high.